In conventional systems of the Cyclotron type the particles are accelerated in a high-frequency electric field set up between hollow segmental electrodes, termed dees, the particles being constrained by a constant transverse magnetic field to spiral outwardly in a path centered on the field axis. The frequency of the electric driving field, acting intermittently upon the particles, must be correlated with their mass/charge ratio which therefore must be the same for all particles to be accelerated in synchronism. Moreover, the sense of acceleration and therefore the direction of rotation depends on the polarity of the particle.
If an attempt were made to accelerate a gaseous plasma in such systems, the polarity-dependent direction of motion of the particles and the diversity of their mass-charge ratios would cause turbulence and untimely collisions between particles traveling at different velocities; the resulting nonuniformity in the speeds of particle streams prevents the establishment of controlled conditions for the desired nuclear or chemical reactions.
In Tokomak-type or Betatron-type accelerators, particles of different polarities are driven in opposite directions by a magnetic field, perpendicular to their orbital plane, whose intensity increases monotonically during each propulsion cycle. When driving a plasma, most of the field energy is tranferred to the electrons, which causes power losses and excessive turbulence of the plasma flow.
Another conventional way of imparting high kinetic energies to molecular particles is by heating a gas to an elevated temperature, such as that produced by a plasma arc. This method of particle acceleration, however, is uneconomical since it produces a wide range of particle energies, not confined to the characteristic energy level of a desired reaction, in accordance with the Maxwell-Boltzmann law of energy distribution in a heated gas, with consequent reduction in the efficiency of the process. Moreover, the unwanted energy bands may also give rise to parasitic side reactions.